<?php

namespace App;

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Loader\Configurator\RouteConfigurator;
use Symfony\Component\Routing\Matcher\UrlMatcher;
use Symfony\Component\Routing\RequestContext;
use Symfony\Component\Routing\RouteCollection;

class Router
{
  use Singleton;

  private RouteCollection $routes;
  private RouteConfigurator $configurator;

  public function __construct()
  {
    $this->routes = new RouteCollection();
    $this->configurator = new RouteConfigurator($this->routes, $this->routes);

    $this->addRoutes();
  }

  /**
   * match the current url against the routes.
   * also add preflight CORS headers on OPTIONS requests.
   */
  public function run(): Response
  {
    $request = Request::createFromGlobals();

    if ($request->isMethod("OPTIONS")) {
      $response = new Response();
      $response->headers->add([
        "Access-Control-Allow-Origin" => "*",
        "Access-Control-Allow-Methods" => "GET, POST, PUT, DELETE, OPTIONS, PATCH, HEAD",
        "Access-Control-Allow-Headers" => "X-Requested-With, Content-Type, Authorization",
      ]);

      return $response;
    }

    $context = new RequestContext();
    $context->fromRequest($request);

    try {
      $matcher = new UrlMatcher($this->routes, $context);
      $match = $matcher->matchRequest($request);

      $class = $match["_controller"][0];
      $method = $match["_controller"][1];

      return (new $class)->$method();
    } catch (\Exception $exception) {
      return new ErrorResponse(ErrorCode::UNKNOWN, "Unknown error occured");
    }
  }

  /**
   * add routes from the routes file
   */
  private function addRoutes(): void
  {
    $routes = include_once(__DIR__ . "/routes.php");
    $routes($this->configurator);
  }
}